caucase.test: Reuse caucased datadir when running multiple tests.

3 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
passed SlapOS.Eggs.UnitTest-Master.Python2

00:17:53

passed SlapOS.Eggs.UnitTest-Master.Python3

00:13:02

passed SlapOS.Eggs.UnitTest-Master.Python3

00:12:50